The Effect of Sapcing Plantation on the Strength Properties of Wood from Taiwania in Taiwan

植栽距離對省產台灣杉強度之影響

唐讓雷(Jung-Lei Tang)

《林產工業》 11卷2期 (1992/06) Pp. 51-59

摘要

台灣杉材（Taiwania cryptomerio ides）取自本省溪頭實驗林區約廿年生之立木作為強度性質測定試驗，這些年幼林木之材質趨向隨樹幹高度部位增加而減低其抗彎破壞係數，衝擊抗力，抗壓縮強度值以及木材之比重，說明幹材內幼齡比例含量隨伴高度增加。若試材取自低裁植密度，亦即栽植距離大之試區，其風倒立木木材強度性質較未受害木為弱，然而由高栽植密度試區內所取之試材則並未獲得相間結果。台灣杉材測試結果趨向栽植距離增大而強度減低，此結果述明較大栽植間距使得林木生長加速，可能造成台灣杉材材質不利之影響，材質降低之緣因可能來自形成較少細胞壁組成之木質部，這些因素也導致本研究中木材比重之試驗值顯著降低。由本試驗與其他相關研究資料中指出，樹齡與生育地之變異對台灣杉材強度影響各異而顯著。

關鍵字

台灣杉材 ； 林木生長 ； 人造林 ； 木材強度 ； 栽植距 ； 幹材內變異 ； 風害木 ； 樹齡與生育地

並列摘要

The mechanical properties of Taiwania wood (Taiwania cryptomericides) was tested using the planted trees sampled from approximately twenty year old trees at Chi-Tou experiment forest in Taiwan. The wood obtained from the young trees showed a general trend of increasing height of tree trunk with decreasing MOR, shock resistance, compression strength, and specific gravity, indicating an increase in the proportion of juvenile wood content. The wind fall damaged trees did show a lower strength of wood as compared to that of the normal standing trees when the trees were sampled from a wide spacing plantation plot. The same result was not found, however, for testing those of the wood taken from the trees at sampled plots with a narrower spacing of plantation. The wood of Taiwania showed a tendency of weakening its strength with increasing the spacing of plantation. This result proposed that the fast growth of tree as a result of having a larger growth space resulted in a detrimental effect of Taiwania wood. A lower quality of wood with possibly less thickness of cell wall was formed, in general. The significant lowering in the value of the wood density was also observed. There were also indications that, from this and the other studies, the variation of wood property may be accounted for by the age of tree and variation of growth locality or site.

並列關鍵字

Taiwania wood ； Tree growth, Man made forest ； Mechanical property of wood ； Spacing of plantation, Within trunk variation ； Wind damaged wood ； Tree age and site effect